If she is reallllyyyy accommodating, a Sat morning visit to the junkies...under the guise of a visit to the biscuit mill
Fish Hoek & Hout Bay arn't my stomping grounds, though I've heard the party can go down at pakalolo's in Hout Bay http://www.pakalolo.co.za/hb-index.php
The Brass Bell (Kalk Bay) was my first thought, but I dunno if it still the place it once was - Maybe a local could let you know?
The Alma Cafe (Rosebank) usually has big name players, not sure about the food, but the muso's are 100% legit - https://www.facebook.com/The-Alma-Cafe-159089414146612/
Also seen some proper muso's play Cafe Roux in Noordhoek - https://www.facebook.com/caferouxCapeTown/
There are other places (plenty in the cbd, Straight No Chaser has some cool music, The Crypt is always good for jazz and anywhere where The Stone Jets play is interesting!), but these popped into my mind. Anyone else?